低透气性特厚煤层工作面高位抽放技术应用

Application of Gas Drainage by High-located Roadway from Extra-thick Coal Seam with Low Gas Permeability

特厚松软高瓦斯低透气性煤层,虽然经过2～3a的预抽,但在工作面回采过程中,上隅角及回风流中瓦斯超限依然是安全生产中的难题,充分利用钻孔抽放回采后顶板岩石冒落后形成的裂隙带中瓦斯,既可提高瓦斯抽放量,改变采场后放瓦斯流场,又能较好地解决工作面瓦斯超限问题,取得了良好效果。

Though gas pre-drainage has been practised in extra-thick broken coal seam with low gas permeability for 2~3 years, the disallowed gas concentration still exists at the upper corner angle and in the air current during the extraction of coal face. Full gas drainage by bore-holes from the fractured zone formed after roof caving can not only raise gas drainage volume and change gas flow field behind the stope, but also solve disallowed gas concentration in working face. Good results were obtained.